Discharge head and fire protection system utilizing said head

ABSTRACT

A fire protection system and a discharge head utilized in the system in which the head is actuated by a release of a thermal responsive link for permitting the extinguishant to discharge. In the event the extinguishant pressure in each head does not attain a predetermined value, the head will not be opened despite release of the fusible link, unless the temperature in the vicinity of the head reaches a predetermined, relatively high value.

United States Patent Marsh July 8, 1975 [5 DISCHARGE HEAD AND FIRE 3,722,596 3/1973 Livingston 169/37 x PROTECTION SYSTEM UTILIZING SAID HEAD Primary Examiner-M. Henson Wood. Jr.

Assistant Examiner-Michael Mar [75] Inventor. William S. Marsh, Needham, Mass. Attorney Agent or Firm Lane' Aitken' Dunner & [73] Assignee: Factory Mutual Research Ziems Corporation, Norwood, Mass.

[22] Filed: Sept. 9, 1974 [57] ABSTRACT [2]] A pl. NO; 504,283 A fire protection system and a discharge head utilized in the system in which the head is actuated by a release of a thermal responsive link for permitting the [52] 169/16; 169/37; 169/42 extinguishant to discharge. In the event the extinguish- Cl. ant pressure i each head does not ta n a p deter Field of Search 38, 39, 40, 41, mined value the h not be opened e p e e 169/16 42 lease of the fusible link, unless the temperature in the vicinity of the head reaches a predetermined, rela- [56] References Cited tively high value.

UNITED STATES PATENTS 8/1972 Livingston l69/37 10 Claims, 3 Drawing Figures DISCHARGE HEAD AND FIRE PROTECTION SYSTEM UTILIZING SAID HEAD BACKGROUND OF THE INVENTION This invention relates to a fire protection system and a discharge head utilized in the system and, more particularly, to such a system and head in which the opening of each head is controlled in response to predetermined conditions.

Automatic sprinkler systems for protecting industrial and commercial properties and employing thermally releasable discharge heads for installation near the top of the space to be protected are well known. The discharge heads utilized in such systems are supplied with a suitable extinguishant, such as water, by a pipe network of mains, risers, crossrnains, and branches. A majority of the heads used in these systems are in the form of sprinkler heads that have a discharge opening normally closed by a plug retained by a thermal fuse and a collapsible linkage bridging an external loop or yoke. Upon actuation of the head by collapse of the linkage, the extinguishant stream issuing from the throat impinges against a serrated deflector disc to form a hemispherical pattern of droplets simulating the characteristics of rain.

However, in buildings where the heat of a localized high-challenge fire establishes a fire column or plume of heights in excess of twenty feet, the fire plume often flares out beneath the ceiling of the protected space and directly actuates numerous heads located at such a distance from the fire that they are ineffective to deliver the extinguishant to the surfaces of the materials stored in the building, while the effects of convection and the circulation of hot combustion products throughout the space contribute to the actuation of still more remotely located heads. This contributes not only to redundant and flooding use of the extinguishant but, more significantly, robs extinguishant from the heads located more directly over the fire where it is much more needed.

In US. Pat. No. 3,682,251 issued on Aug. 8, 1972, and assigned to the same assignee as the present invention, a fire protection system is disclosed in which a plurality of discharge heads are adapted to be thermally actuated in response to a predetermined temperature. However, the number of actuated heads that are actually opened are limited by means of a pressure floor in which a predetermined extinguishant pressure at each individual head must be exceeded before the head will open.

Although this type system has considerable advantages, it has since been discovered that two mutually exclusive factors influence the performance of the system. On one hand, it was found to be extremely desirable to actuate the heads at a relatively low temperature, such as approximately l50200, to insure that heads located immediately above the fire would open in a relatively quick manner after initiation of a fire and begin to discharge extinguishant towards the tire to fight it at its early stages.

However, it was also discovered that this relatively low actuation temperature often caused several of the heads to be actuated prematurely due to the fact that their temperature responsive mechanisms were more susceptible to external factors, such as air currents, ambient temperatures, and the convective circulation of gaseous products of combustion, etc. As a result, the

heads would often be prevented from opening in a logical sequence, i.e., in direct proportion to their distance from the location of the fire. This plus the fact that the above-mentioned pressure floor would limit the number of heads that opened also often resulted in heads being opened which were located a greater distance from the fire than heads that were prevented from opening. Also, in the event some of the heads, after being actuated, were prevented from opening due to lack of pressure, they remained closed even if the magnitude of the fire increased to the extent that discharge of extinguishant from all available sources was essential, despite the lack of the predetermined pressure.

A way of overcoming this illogical operation would be to raise the response temperature of the individual heads, such as to a value of approximately 350450. In this manner, the above-mentioned external influences prevailing in the building would have less effect upon the heads, and the heads located the closest to the fire would open in a logical sequence. However, the existence of this relatively high response temperature causes the system to respond slowly to the existence of a fire, often to an extent that would permit the fire to reach proportions that rendered it impossible to extinguish.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a fire protection system and a discharge head utilized therein in which each head will open upon the existence of a predetermined temperature and extinguishant pressure.

It is a further object of the present invention to provide a system and head of the above type in which each head will open in response to the existence of a predetermined, relatively high, temperature regardless of the value of the extinguishant pressure.

It is a further object of the present invention to provide a system and head of the above type in which the response mechanism in the head is relatively precise in operation, yet inexpensive in cost.

Towards the fulfillment of these and other objects, the discharge head utilized in the system of the present invention comprises a body member for containing pressurized extinguishant, said body member having an inlet for connecting to a source of said extinguishant and an outlet for discharging said extinguishant, closure means for said outlet, linkage means for applying a force against said closure means greater than, and in an opposite direction to, the force of said extinguishant against said closure means to retain said closure means in an operative position relative to said outlet where it prevents the discharge of extinguishant from said outlet, said linkage means adapted to respond to a predetermined fire condition in its vicinity for releasing its force, and adhesive means for securing said closure means in said operative position, said adhesive means adapted to release said closure means in response to the pressure of said extinguishant in said body member exceeding a predetermined value, said closure means being forced from said operative position by said extinguishant upon the existence of said fire condition and said predetermined extinguishant pressure to permit the discharge of said extinguishant from said outlet.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a building having the fire protection system of the present invention installed therein;

FIG. 2 is a vertical cross-sectional view of a discharge head utilized in the system of FIG. 1; and

FIG. 3 is an enlarged partial view of a portion of the head of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of the drawings, a building is shown in phantom lines which is equipped with an automatic fixed fire protection system embodying features of the invention. The system comprises a buried feed main 12 connected to a municipal water supply line 14 for delivering the extinguishant, in this case water, via a horizontal line 16, to a riser 18. The riser 18 is connected to a piping system suspended near the ceiling of the building 10 in a conventional manner. The piping system includes a crossmain 20 which is connected to a plurality of branch lines 22 spaced along the crossmain and extending perpendicular thereto. The riser 18 is connected to a free end of one of the branch lines 22 for supplying water to the crossmain 20 which, in turn, supplies the water to the other branch lines 22. Each branch line 22 has a plurality of sprinkler heads 24 mounted thereon in a spaced relationship which are operated automatically in response to a fire occurring in the building, as will be described, to deliver a spray of water to the fire. The buried feed main 14 extends beyond the riser l8 and can be connected to risers of other buildings or, in the case of a large building, to other risers in the same building.

A sprinkler head 24 is shown in FIG. 2 and consists of a tubular base member 26 having an externally threaded portion 28 at one end thereof for connection to an internally threaded opening (not shown) in a branch line 22. The other end portion of the member 26 is tapered in two planes to define a seat 30 surrounding a discharge opening.

A yoke 32 has two leg portions (only one of which is shown in FIG. 2) extending from the base member 26 and terminating in an apex 32a. A serrated deflector disc 34 has an externally threaded plug portion 34a extending in an internally threaded bore formed in the apex 32a of the yoke 32 to support the disc 34. A gasket 36 engages the seat 30 of the base member 26 and has a central opening 36a formed therethrough, and a cap 38 extends over the gasket 36 to close the discharge opening, as will be described in detail later.

A collapsible linkage assembly, comprising two substantially T-shaped lever arms 40 and 42, is supported between the base member 26 and the disc 34. One projecting portion of the lever arm 40 engages the cap 38 to maintain it and the gasket 36 against the seat 30, while one projecting portion of the lever arm 42 is supported by the plug portion 34a of the disc 34. The other projecting portions of the lever arms 40 and 42 engage each other, while the ends of the lever arms are engaged by a fusible link 44 extending thereover in a manner to apply aforce to the lever arms of a sufficient amount to maintain them in the position shown. The fusible link 44 may be of any standard material, such as solder, which is adapted to fuse, or melt, at a predetermined elevated temperature, and release itself from the engagement with the lever arms 40 and 42.

Referring to FIG. 3, it is noted that the outer radial portion of the gasket 36 is bent to form an internal shoulder portion which extends over the seat 30. The gasket 36 is cemented to the seat 30 by a supply of adhesive 50 which extends between the latter shoulder portion and the seat. The adhesive 50 may be of any conventional type, such as a commercially available two-solution epoxy cement and is preferably spplied to the shoulder before the latter is placed on the seat 30 which causes a portion of the adhesive to seep outwardly from the seat as shown. The thickness of the adhesive 50 is carefully controlled so that it applies a predetermined bonding force between the gasket 36 and the seat 30.

A supply of solder 52 extends between the upper bent portion of the gasket 36 and a corresponding ledge 38a formed on the cap 38 to secure the cap relative to the gasket. The solder 52 may be of a conventional type and is adapted to melt or fuse at a predetermined elevated temperature in excess of the temperature at which the fusible link 44 melts. For example, the solder 52 can be selected to melt at 500F. and the fusible link 44 can be selected to melt at 165F.

It is thus seen that the cap 38 is normally retained in its position shown in FIGS. 2 and 3 by virtue of the lever arms 40 and 42, the adhesive 50 between the gasket 36 and the seat 30, and the solder 52 between the cap 38 and the gasket 36.

In operation, the heads 24 are installed in the position shown in FIG. 1, with the pressure of the water supplied to each head being insufficient to discharge the cap 38 from the outlet opening 30 due to oppositely-directed force applied to the cap 32 by the lever arms 40 and 42. Upon the temperature in the vicinity of one or more of the heads 24 reaching the fusible temperature of its link 44 which, for the purposes of example, is lF., the link 44 will fuse and fall downwardly by gravity away from the head. However, the cap 38 and the gasket 36 will be secured in the position shown in FIGS. 2 and 3 by the adhesive 50 between the seat 30 and the gasket 36 and by the solder between the gasket 36 and the cap 38. If the force applied to the exposed inner surfaces of the gasket 36 and the cap 38 by the pressure of the water in the base member 26 is of a magnitude to break the adhesive bond between the gasket 36 and the seat 30, the gasket 36 and therefore the cap 38 will be freed for release from the discharge opening under the pressure of the water, thus permitting the water to discharge towards the deflector disc 34.

After fusing of the link 44, in the event the water pressure in the base member 26 is not sufficient to break the adhesive bond between the gasket 36 and the seat 30, the gasket 36 and the cap 38 will close the discharge opening and discharge of the water will be prevented. However, if the temperature in the vicinity of the head rises to the extent that it reaches the melting temperature of the solder 52, which, for the purposes of example, is 500F., the cap 38 will release from the gasket 36 and the water will discharge through the opening 36a in the gasket, despite the absence of a predetermined water pressure in the body member 26. This, of course, provides a failsafe opening of each head in the event the magnitude of the fire increases to the extent that it is no longer desirable to prevent the heads from opening.

In the event that one or more of the heads 24 are opened under the above conditions, the resulting stream of water issuing from the discharge opening will impinge against the serrated deflector disc 34 to form a hemispherical pattern of droplets a portion of which will extend in a radial direction relative to the discharge opening and eventually fall onto the fire, simulating the characteristics of rain.

it is thus seen that according to the present invention each head can be designed to respond to a predetermined temperature and water pressure depending on the fusion temperature of its link 44 and the pressure that will cause a breaking of the adhesive bond between its gasket 36 and seat 30. In this manner, the system can be designed to insure that after a predetermined number of heads 24 have been opened, any additional heads will not be opened despite the fusion of their fusible links 44 unless the temperature rises to the predetermined level sufficient to melt the solder 52. As discussed above, this eliminates the redundant and flooding use of water and prevents heads located a fairly remote distance from the actual location of the fire from being opened and therefore robbing water from the heads directly over the fire in the area where it is critical that they have sufficient pressure, while also permitting failsafe opening of each head in the event a potentially disastrous fire situation is occurring.

It is understood that the discharge head of the present invention is not limited to use as a sprinkler head, but can take other basic forms without departing from the scope of the invention. Also, variations in the type of extinguishant used, as well as other variations of the specific construction and arrangement of the fire protection system and discharge head disclosed above can be made by those skilled in the art without departing from the invention as defined in the appended claims.

I claim:

1. A discharge head for use in a fire protection system comprising a body member for containing pressurized extinguishant, said body member having an inlet for connecting to a source of said extinguishant and an outlet for discharging said extinguishant, closure means for said outlet, linkage means for applying a force against said closure means greater than, and in an opposite direction to, the force of said extinguishant against said closure means to retain said closure means in an operative position relative to said outlet where it prevents the discharge of extinguishant from said outlet, said linkage means adapted to respond to a predetermined fire condition in its vicinity for releasing its force, and adhesive means for securing said closure means in said operative position, said adhesive means adapted to release said closure means in response to the pressure of said extinguishant in said body member exceeding a predetermined value, said closure means being forced from said operative position by said extinguishant upon the existence of said fire condition and said predetermined extinguishant pressure to permit the discharge of said extinguishant from said outlet.

2. The head of claim 1 wherein said closure means includes a gasket secured to said body member by said adhesive means and having an opening registering with said outlet, a cap extending over said gasket, and means for securing said cap to said gasket.

3. The head of claim 2 wherein said means for securing said cap to said gasket comprises solder adapted to melt at a predetermined temperature for releasing said cap from said gasket under the force of said extinguishant and permit said extinguishant to discharge from said outlet and through said gasket opening.

4. The head of claim 3 wherein said predetermined fire condition is a temperature of a lower value than that required to melt said solder.

5. The head of claim 1 further comprising deflector means supported on said body member in a spaced relation to said outlet for deflecting said extinguishant in a generally radial direction from said body member.

6. A fire protection system comprising a plurality of discharge heads mounted in an elevated position in the space to be protected from fire, conduit means connected to a source of pressurized extinguishant, each discharge head comprising a body member for containing said pressurized extinguishant, said body member having an inlet for connecting to said conduit means and an outlet for discharging said extinguishant, closure means for said outlet, linkage means for applying a force against said closure means greater than, and in an opposite direction to, the force of said extinguishant against said closure means to retain said closure means in an operative position relative to said outlet where it prevents the discharge of extinguishant from said outlet, said linkage means adapted to respond to a predetermined fire condition in its vicinity for releasing its force, and adhesive means for securing said closure means in said operative position, said adhesive means adapted to release said closure means in response to the pressure of said extinguishant in said body member exceeding a predetermined value, said closure means being forced from said operative position by said extinguishant upon the existence of said fire condition and said predetermined extinguishant pressure to permit the discharge of said extinguishant from said outlet.

7. The system of claim 6 wherein said closure means includes a gasket secured to said body member by said adhesive means and having an opening registering with said outlet, a cap extending over said gasket, and means for securing said cap to said gasket.

8. The system of claim 7 wherein said means for securing said cap to said gasket comprises solder adapted to melt at a predetermined temperature for releasing said cap from said gasket under the force of said extinguishant and permit said extinguishant to discharge from said outlet and through said gasket opening.

9. The system of claim 8 wherein said predetermined fire condition is a temperature of a lower value than that required to melt said solder.

10. The system of claim 6 further comprising deflector means supported on said body member in a spaced relation to said outlet for deflecting said extinguishant in a generally radial direction from said body member. 

1. A discharge head for use in a fire protection system comprising a body member for containing pressurized extinguishant, said body member having an inlet for connecting to a source of said extinguishant and an outlet for discharging said extinguishant, closure means for said outlet, linkage means for applying a force against said closure means greater than, and in an opposite direction to, the force of said extinguishant against said closure means to retain said closure means in an operative position relative to said outlet where it prevents the discharge of extinguishant from said outlet, said linkage means adapted to respond to a predetermined fire condition in its vicinity for releasing its force, and adhesive means for securing said closure means in said operative position, said adhesive means adapted to release said closure means in response to the pressure of said extinguishant in said body member exceeding a predetermined value, said closure means being forced from said operative position by said extinguishant upon the existence of said fire condition and said predetermined extinguishant pressure to permit the discharge of said extinguishant from said outlet.
 2. The head of claim 1 wherein said closure means includes a gasket secured to said body member by said adhesive means and having an opening registering with said outlet, a cap extending over said gasket, and means for securing said cap to said gasket.
 3. The head of claim 2 wherein said means for securing said cap to said gasket comprises solder adapted to melt at a predetermined temperature for releasing said cap from said gasket under the force of said extinguishant and permit said extinguishant to discharge from said outlet and through said gasket opening.
 4. The head of claim 3 wherein said predetermined fire condition is a temperature of a lower value than that required to melt said solder.
 5. The head of claim 1 further comprising deflector means supported on said body member in a spaced relation to said outlet for deflecting said extinguishant in a generally radial direction from said body member.
 6. A fire protection system comprising a plurality of discharge heads mounted in an elevated position in the space to be protected from fire, conduit means connected to a source of pressurized extinguishant, each discharge head comprising a body member for containing said pressurized extinguishant, said body member having an inlet for connecting to said conduit means and an outlet for discharging said extinguishant, closure means for said outlet, linkage means for applying a force against said closure means greater than, and in an opposite direction to, the force of said extinguishant against said closure means to retain said closure means in an operative position relative to said outlet where it prevents the discharge of extinguishant from said outlet, said linkage means adapted to respond to a predetermined fire condition in its vicinity for releasing its force, and adhesive means for securing said closure means in said operative position, said adhesive means adapted to release said closure means in response to the pressure of said extinguishant in said body member exceeding a predetermined value, said closure means being forced from said operative position by said extinguishant upon the existence of said fire condition and said predetermined extinguishant pressure to permit the discharge of said extinguishant from said outlet.
 7. The system of claim 6 wherein said closure means includes a gasket secured to said body member by said adhesive means and having an opening registering with said outlet, a cap extending over said gasket, and means for securing said cap to sAid gasket.
 8. The system of claim 7 wherein said means for securing said cap to said gasket comprises solder adapted to melt at a predetermined temperature for releasing said cap from said gasket under the force of said extinguishant and permit said extinguishant to discharge from said outlet and through said gasket opening.
 9. The system of claim 8 wherein said predetermined fire condition is a temperature of a lower value than that required to melt said solder.
 10. The system of claim 6 further comprising deflector means supported on said body member in a spaced relation to said outlet for deflecting said extinguishant in a generally radial direction from said body member. 